pkg/db: make local package database's path relative to installation name

Instead of `(version)`, use `(get-installation-name)` for the path
of the local database used by the GUI package manager.

pkgs/racket-pkgs/racket-doc/pkg/scribblings/db.scrbl

@@ -2,7 +2,8 @@
 @(require (for-label racket/base
                      racket/contract/base
                      pkg/db
-                     syntax/modcollapse))
+                     syntax/modcollapse
+                     setup/dirs))
 
 @title[#:tag "db"]{Package Catalog Database}
 
@@ -40,8 +41,9 @@ strings. Otherwise, unknown fields are represented by empty strings.}
 @defparam[current-pkg-catalog-file file path-string?]{
 
 A parameter that determines the file path used to hold the SQLite
-database. The default value is in the user's add-on directory and in
-a version-specific subdirectory.}
+database. The default value is in the user's add-on directory as
+determined by @racket[(find-system-path 'addon-dir)] and within a
+subdirectory determined by @racket[get-installation-name].}
 
 
 @deftogether[(

racket/collects/pkg/db.rkt

@@ -5,6 +5,7 @@
          racket/path
          racket/file
          version/utils
+         setup/dirs
          db/private/pre)
 
 (provide 
@@ -120,7 +121,7 @@
 (define current-pkg-catalog-file
   (make-parameter (build-path
                    (find-system-path 'addon-dir)
-                   (version)
+                   (get-installation-name)
                    "pkgs"
                    "catalog.sqlite")))